Today Twitter announced it will be censoring information based on global codes of conduct. “As we continue to grow internationally, we will enter countries that have different ideas about the contours of freedom of expression,” the company wrote on its blog. “Some differ so much from our ideas that we will not be able to exist there. Others are similar but, for historical or cultural reasons, restrict certain types of content, such as France or Germany, which ban pro-Nazi content.”

“Starting today, we give ourselves the ability to reactively withhold content from users in a specific country—while keeping it available in the rest of the world.”

Twitter also says that if and when it is forced to exercise this tactic, it will be forthcoming about it. The site has partnered with ChillingEffects, a transparency organization that will record and report any tweets that have been withheld.

Prior to this change, Twitter would remove offending tweets after the fact, not taking action before they were actually published.

It’s a controversial move for the site, which was crucial during the Middle Eastern uprisings that began last spring. Under these new regulations, it’s possible that political demonstrations won’t be able to use this medium. Many repressive regimes where Twitter is available, condemn speaking out against dictators. Facebook tried to distance itself from getting overly tied to being an international political mouthpiece as well.

However, to a degree and if it’s even possible, Twitter might be doing censorship right. For instance if someone in Burma used Twitter to critique his government, another Burmese citizen on the site would see this warning:

Elsewhere in the world the tweet would appear. Withholding these posts will be based on the IP address of the user.

It’s a preemptive move to avoid litigation, and one that Twitter will have to take at some point as it grows. Now it’s just trying to ease in new policies while there isn’t any hype around a specific issue, and without users and authorities simultaneously breathing down its neck. Still, given its position as an international soapbox, users in some parts of the world have more reason for concern.